Fractionating tower



July 30, 1940. D, L, D'Q DS 2,209,675

FRACTIONATING TOWER Filed Sept. 6, 1958' 5 Sheets-Sheet 1 DAN L. 00005 y 1940- D. L. DODDS FRACTIONATING' TOW ER Filed Sept. 6, 1938 5 Sheets-Sheet 2 y 1940. D. 1.. DODDS 2,209,675

FRAGTIONATING TOWER I Filed Sept. 6, 1938 5 Sheets-Sheet 5 July 30,. 1940.

D. nonps FRACTIONATING TOWER Filed Sept. 6, 19 8 5 Sheets-Sheet 4 DA/v L; D0005 July30, 1940. h D, .mbonog I 2.209575 FRACTIONATING TOWER Fild'sept. 6, 1958. s Sheets-Sheet s DAN D0005 Patented July 30, 1940 UNITED STATES PATENT 7 OFFICE f I mar-1:13: 2; rowan 1 Dan L. Dodds, Galveston, Tex. Application 38:32:: l lo. 228,561

This invention relates to a fractionating tower.

The invention embodies certain improvements over that type of fractionating tower disclosed in my co-pending application, Serial No. 197,164,

5 filed in the United States Patent Oiiice on March 21, 1938.

An object of the invention is to provide an apparatus of the character described specially designed to be employed for the purpose of separating vapors whereby those not of the desiredcharacteristics may be condensed and separated from those which are of the desired characteristics, the condensed vapors being returned, if desired, for further treatment. l More specifically the invention relates to apparatus designed to be employed in fractional distillation, absorption, condensation or stripping of liquids or gases as the same move in an approximately horizontal direction through the tower.

The invention embodies the advantages of that type of construction disclosed in the co-pending application above referred to and in addition thereto novel types of sealing pans and bubble caps mounted invertical partitions and of such novel arrangement and construction as to materially increase the capacity of the tower and more,

efllciently separate the lighter from the heavier vapors, the latter being condensed out and returned for such retreatment as may be desired. With the above and other objects in view the invention has particular relation to certain novel features of construction, arrangement of-parts, and use, examples of which are given in this specification and illustrated in the accompanying drawings, -wherein:

Figure 1 shows a fragmentary, vertical-sectional view taken on the line i-l of Figure 3.

Figure 2 shows a fragmentary, vertical-sec 4o tional view taken on the line 2-2 of Figure 3. Figure 3 shows a fragmentary, longitudinal, sectional view taken on'the line 3+4 of Figure 2.

Figure 4 shows a fragmentary, perspective view, partly in section of one of the sealing pans 5 employed. 1

Figure 5 shows a plan view of another embodiment of said pan.

Figure 6 shows a plan view of still another em bodime'nt.

Figure 7 shows a fragmentary, side elevation, partly in section, showing-a sealing pan assembly. Figure 8 shows a cross-sectional view of said assembly taken on the line 8-8 of Figure 7.

Figure 9 shows a fragmentary, bottom view of 55 the sealing pan illustrating another embodiment.

Figure 10 shows a plan view of still another embodiment of the sealing pan.

4 Figure 11 showsa cross-sectional view thereof taken on the line ll-li of Figure 10.

Figure 12 shows a fragmentary, vertical-sec- 5 tional view of the tower illustrating the type of sealing pan assembly shown in Figure 10, and Figure 13 shows a side view, partly in section, of the complete tower.

Referring now more particularly to the draw- 10 ings wherein like numeralsof reference desig nate the same parts'in each of the figures, the numeral I designates an outer shell or container which is preferably so disposed that the fluid will follow, in general, an approximately horizontal 16 course from inlet to outlet. Mounted in the shell and spaced 9. selected distance apart are similar vertical partitions 2 which are anchored to the walls of the container by brackets as 3 and whose margins are in sealed engagement with the walls of the container. The partitions have the rectangular openings 4 therethrough which are preferably in alignment. Series of collecting, or sealing, pans are mounted in the respective openings of the partitions. as best shown in Figures 1, 2 and 7. As. shown in Figures 1, 2, ll-and 12, bubble caps hereinafter more particularly described are combined with the sealing pans of the assemblies shownin said figures. The type of collecting pan; or sealing pan, illustrated in 30 Figures 1, 2 and 3 is indicated by the numeral 5,

Figure 5. Each pan of this type has a surround ing marginal upstanding flange G and has the rectangular; transversely extending, upstanding weirs I, I. The pens are arranged in series, one 35 series for each partition 2, and the pans of each i series are arranged one above the other as shown in Figures 1 and 2. The ends of thepans are anchored to the corresponding partitions by means of theirbrackets as 8, as illustrated in Figures-1, 2, 3,7 and 12. Depending from'the pans 5 are the bubble caps 9. The bubble caps of each pan depend down into the pan beneath. They extend transversely of the pan as shown more clearly in Figure 3 and are preferably rec- .tangular inhorizontal cross-sectional contour.

The lower ends of the bubble caps are serrated forming the deep notches II). The apexes of the notches are approximately on a levelwith, .or slightly above the upper margins of the weirs I, and, it is to be noted, that the upper margins of the weirs I are located slightly beneath. the upper margins of the surrounding sides or flanges 6 of the corresponding pans 5. The forward walls of the bubble ca s of each pan, of the form rear. The condensate rising above the level of shown in Figures 1, 2 and 3 have a common rear wall H which is provided with the inlet openings I 2 for the advancing vapors. The forward wall i3 of each bubble cap is closed.

The vapors to be dephlegmated advance from the entrant end of the tower, in the direction of the arrow in Figure 3, toward the discharge end passing through the openings of each series into the corresponding bubble caps. The heavier ele-,- ments will be condensed on the walls of the bubble caps and drained down'into the respective pans beneath so as to eventually maintain the serrated edges of the caps submerged, the lighter elements bubbling through the entrapped liquid and passing on from one series of bubble caps to the next and eventually collecting in the flnal compartment l4 and passing thence outwardly through a suitable vapor outlet line [5. Each partition 2 is provided, near its lower margin with a transverse return slot I6, andin front of said slot, is provided with a transverse baflle I! which extends upwardly the required distance above the upper margin of the corresponding slot thus provided'ior the return of the residue from compartment to compartment.

The condensate will collect in the pans I of the respective series.

The weirs of the pans i deflne the depending pockets l8, l9 into which the bottoms of the respective pans are formed. Return pipes 20 lead from the respective pockets l8, of the pans of one series into the corresponding end pockets l8 of the corresponding pans in the rear and return pipes 21 lead from the respective pockets is of the pans of one series into the corresponding end pockets I! of the corresponding pans in the the corresponding weirs of any pan will therefore overflow into the pocket i8,.or IQ, of said pan and will flow thence through the corresponding pipe leading rearwardly therefrom to the corresponding pocket of the next pan in the rear, thus overflowing the weir above and flowing into the corresponding pan. The condensate thus eventually flowing rearwardly from one series of pans to the next series in the rear. Any excess condensate collecting into and overflowing any of the pans will fall down into the bottom of the shell or tower and will return from compartment to compartment through the slots [8 overflowing the corresponding baiiies l1 and thus rising to a level to submerge the lower serrated ends of the lower bubble caps 8.

It will be noted that the returning condensate entering each pan from the corresponding pan in front will enter at one end of the pan and travel along said pan overflowing the weir at the other end thereof and continuing its rearward course.

In Figure 4 there is shown another embodiment of the collecting pan, or sealing pan, Ia having the end weirs as 1a and provided with the inlet openings l2a in the forward wall. with this type of pan the condensate overflowing the end weirs, as Ia, will pass into the end pockets as l8a. This type of pan 5a is provided with overflow pipes 200, at each end and Ila arranged intermediate the ends whereby the excess condensate may overflow from one pan into the pan beneath. In other respects the pan 5a is substantially similar to the pans I in Figures 1 and 2.

In the form shown in Figures 6, 'i and 8 another embodiment of the collecting pan or seal ing pan is'illustrated and indicated by the numeral 5b. It has the upstanding marginal rim or flange 6b and the diagonally opposite weirs lb. The ends of the pans 5b are secured to the corresponding partitions 2 by the brackets 8 as shown in Figure '7. This type of pan has the overflow pipes 20b, 2lb for permitting return circulation of the condensate from series to series as hereinabove described.

As clearly shown in Figure 8 the pan assembly, embodying the type of pan shown in Figure 6,

does not embody the bubble caps, properly speaking, but depending from each pan, into the compartment beneath, there is a centrally located, longitudinal bafile 22v whose lower margins are serrated providing the notches 23 and the pans are spaced apart vertically to permit the passage of vapor forwardly through between the pans of the series. The upper plate 22 depending into the upper pan 5b is suitably secured to the margin of the partition 2 as also clearly shown in Figures 7 and 8. The vapors passing through the series of pans 5b will be partially condensed, the heavier particles collecting in the pans in the form of condensate was to eventually maintain the lower serrated edges of the plates 22 submerged, the lighter elements bubbling through the entrapped liquid and passing on from one series of pans to the next and eventually collecting in the compartment N.

If desired the baflle, or plate, 22a, as shown in Figure 9 depending from the bottom of the pan 5c, may be formed sinuous, with its lower margins serrated thus giving somewhat greater capacity for the passage of the lighter elements and the condensation of the heavier elements.

Referring to Figures 10' to 12, inclusive, there is there shown another embodiment of the sealing pan or collecting pan 5d of the general shape as that of the pan 5b and having the diagonally opposite receiving pockets I 8a, in, connected with which are the pipes 200, Zlc. The pockets l8a, l9a are separated from the pan by the respective weirs 10 whose upper margins are on a lower level than the upper margin 80 of the pan 5d. These pans are anchored to the corresponding partitions by the end brackets 8 as illustrated in Figure 12. Depending from each pan'into the compartment beneath are bubble caps similar in construction and arrangement to those illustrated in Figures 1 and 2 and have a similar purpose.

wardly into the compartment beneath.

It will thus be observed that the liquid as it collects will pass from pan to pan either in a' rearward direction, or in a downwardly direction, and will finally collect at the bottom of the corresponding compartment and will pass thence from compartment to compartment tothe initial compartment from which it may be discharged by any suitable discharge equipment provided for the purpose. This is very desirable as it allows the particles of the lighter fraction or constituents of a lower boiling point to pass on rather than to be'entrained in constituents ofa higher boiling point and to be carried back along the tower where it may pass out as residue.

In this type of equipment during operations there is a continuous flow of vapor forward in the tower until the vapors reach the final compartment, in the present illustration indicated by the numeral l4, and from which it is conducted out by the vapor line l5 and there is also.

of refluxing, or absorption, liquid up through the final compartment i4 and which is connected into the forward ends of the pockets l8 of the respective pans in said final compartment.

It is, of course, to be observed that the vapors flowing through the tower from inlet to outlet will be maintained under the required pressure and temperature.

The fluid to be fractionated enters the initial compartment 25 through the delivery pipe 26. The compartment 25 may contain a heating coil 21, if desired, into which a heating element may be delivered through a pipe 28. Other heating means may be employed, if desired, or in some cases this heating element may be dispensed with. Leading from the compartment 25 there is an. outletline 25 whose inner end extends up into said compartment to the desired liquid level and may be surrounded and enclosed by a vertical hood 30 forming a trap. This hood may be supported in any selected manner.

What I claim is:

1. In a fractionating tower having a shell and a vertical partition whose margins are in sealed engagement with the walls of the shell, said partition having an opening therethrough; a series of collecting pans mounted in said opening one above the other, each pan havingupstanding side walls and end walls, means for anchoring the pans to the partition, bubble caps depending from the pans, the caps of each pan above depending downwardly into the pan beneath and whose lower ends are serrated forming deep notches whose apexes are slightly beneath the upper margins of said walls, weirs defining areas of the pans and whose upper margins are slightly beneath the apexes of the notches, inlet and outlet conduits one entering the pan beneath the level of the corresponding weir and the other leading from the pan beneath the level of the other weir'whereby fluid may flow through oneconduit and overflow said weirs and pass outwardlythrough the other conduit.

2. In a fractionating tower having a shell and a vertical partition whose margins are in. sealed engagement with the walls oi. the shell, said partition having an opening therethrough; .a

series of collecting pans mounted insaid-opening one above the other, each pan having upstanding side walls and end walls, means for anchoring the pans to the partition, bubble caps depending from the pans, the caps of each pan above depending downwardly into the pan beneath and whose lower ends are serrated forming deep notches whose apexes are slightly beneath the upper margins of said .walls, weirs defining areas of the pans and whose upper-margins are slightly beneath the apexes of the notches, inlet' and outlet conduits one entering the pan beneath the level of the corresponding weir and the otherleading from the pan beneath the level of the other weir whereby fluid may flow through one conduit and overflow said weirs and pass outwardly through, the other conduit and 'an overflow pipe through which fluid may flow from one pan into another pan.

3. In a fractionating tower having a shell and pans in said opening and anchored to the partition, baflling means depending from each pan whose lower margins are serrated forming notches. the baiiiing means-depending from one pan above into the pan beneath, the apexes of said notches being located beneath the upper margins of the walls of the pan into which the baille extends whereby to permit a gaseous fluid to flow forwardly through the pans in one direction, an inlet conduit entering each pan, an

outlet conduit leading from each pan and means for causing the flow of condensate collecting in the pans in a direction the opposite of that of 45 the gaseous fluid.

DAN L. DODDS. 

